Tuning tube

ABSTRACT

A tuning tube for an exhaust gas muffler is formed by attaching a semicircular channellike member to a transverse partition.

United States Patent [72] Inventor Paul A. R111! [56] References CitedJacks, UNITED STATES PATENTS [21] Appl. No. 834,824

- 2,337,300 12/1943 Noblltt et a1 181/54 [22] Filed June 19, 19692,922,485 1/1960 Muller 1 181/54 [45] Patented Jan. 26, 1971 2,950,7778/1960 Deremer 181/54 [73] Assignee Tennecolnc.

Houston 3,104,734 9/1963 ludlow et a1. 181/48 acorporafionomelawambymeme 3,198,284 8/1965 Powers .1 181/54 assignments 3,209,438 10/1965Br0wn.... 181/54X 3,243,012 3/1966 Powers 181/54X 3,263,772 8/1966 Irwinet a1. 181/59 3,353,627 11/1967 Heath 181/48 FOREIGN PATENTS 1 TUNI NGTUBE 1,728,228 1/1930 Australia 181/58 5 Claims 2 Drawing Figs. PrimaryExaminerRobeIt S. Ward, .11. [52] US. Cl 181/59, Atwmey HameSS, Dickey &pierce 181/54 [51] Int. Cl F0ln1/02,

F01n1/12 ABSTRACT: A tuning tube for an exhaust gas muffler is [50]Field of Search 181/47, 48, formed by attaching a semicircularchannellike member to a 54, 57-59 transverse partition.

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I PATENTEn masmn AW NW Wccccc INVENTOR. 11/ A E??? TUNING TUBE BRIEFSUMMARY OF THE INVENTION It is the purpose of this invention to improvethe tuning tube construction of a sound attenuating muffler for flowinggases, especially exhaust gas mufflers.

The invention accomplishes this purpose by means of an assembly ofpartition and passage defining member in which the partition forms alengthwise part of the passage wall. The invention simplifies andeconomizes the manufacture of mufflers and provides a better corrosionresistance because the passage may be located in a hotter part of themuffler.

While the invention is illustrated in connection with a combinationpartition-tuning tube assembly, the basic idea may be used in otherlocations and to incorporate other silencing techniques.

DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal cross sectionthrough an exhaust gas muffler embodying the invention; and

FIG. 2 is a reduced size cross sectionalong the line 22 of FIG. 1.

DETAILED DESCRIPTION OF THE INVENTION The muffler I has an elongatedtubular shell 3 which is closed at its inlet end by a header 5 and atits outlet end by a header 7. The header 5 has an inwardly turned collar9 in which is secured an inlet bushing 11; while the outlet header 7 hasan inwardly turned collar 13 in which is secured an outlet bushing 15.An inlet gas flow tube 17 is supported in the inlet bushing 11 and anoutlet gas flow tube 19 is supported in the outlet bushing 15.

The space within the shell 3 is subdivided into three longitudinallyadjacent chambers 21, 23, and by a pair of flat transverse walls orpartitions 27 and 29 which have outer peripheral flanges 31 that aresecured to the shell 3. The inlet tube 17 empties into the centralchamber 23 and gas from the chamber 23 flows backwardly through anopening 33 in the partition 27 to reach the outlet chamber 21. Gas inthe chamber 21 flows out of the muffler by entering the left end of theoutlet tube 19. The inlet tube 17 may have a first louver patch 35 whichis surrounded by a closed shell 37 to form a high frequency attenuatingspit chamber 39. It may have a second louver patch 41 in the projectingend of the tube to open into the chamber 23 and permit bypassing to alouver patch 43 in that portion of outlet tube 19 which is located inthe chamber 23. The tube 17 is supported on partition 27 by way of theshell 37 which is carried by a collar 45 in the partition. The outlettube has a louver patch 47 which is surrounded by closed shell 49 toform a spit chamber 51 for attenuating high frequencies, the shell 49being supported in a collar 53 in the partition 29 so that it along withthe collar 55 in the partition 27 supply additional support for the tube19.

In accordance with this invention, the flat wall of the partition 29 isprovided with an opening 57. Secured on the chamber 25 face of thepartition 29 is a semicircular, channellike passage defining member 59which is closed at one end 61, this end being located adjacent theopening 57. The other end 63 of the member 59 is open whereby thecenterline length of the passage 64 from hole 57 to end 63 constitutes alength of tuning passage which along with its cross-sectional area,cooperates under the Helmholtz fonnula with the volume of chamber 25 tosilence a predetermined and precalculated sound frequency. In contrastto the usual tuning passage structures wherein the passage axis isperpendicular to the partition, it will be observed that it is parallelin the present arrangement.

The member 59 may be assembled with the partition 29 by spotwelding orother suitable means but preferably has several tabs 65 formed on itwhich project through suitable slits 67 in the partition 29 and are thenbent as seen at 69 to firmly secure the member 59 to the partitionmember 29.

It is apparent that an indentation could be formed in the wall 29 tocooperate with the illustrated shape ofthe channellike member 59 or withother shapes, including flat, of the member 59 to form the tuningpassage 64. By closing the end 63, the passage 64 will serve as aquarter wave length tuner or quincke tube. Other modifications, such asthe use of louvers or perforations in the member 59, may also beemployed without departing from the spirit of the invention.

In operation, the bushings 11 and 15 are clamped to conduits in a gasflow system, such as an automotive exhaust system, so that gas entersthe bushing 11 to flow through tube 17 to chamber 23. High frequencysound and roughness is attenuated en route in spit chamber 39. Somewhatlower frequencies are attenuated by the louvers 41. Some gas can bypassto the outlet tube through louver patch 43 but most of it reversesdirection and flows through hole 33 to chamber 21 where it enters outlettube 19. In flowing to the outlet bushing 15 high frequency sounds androughness are further attenuated in spit chamber 51. The length andcross-sectional area of tuning passage 64 and the volume of the chamber25 are related so as to be tuned to attenuate a desired relatively lowfrequency.

I claim:

I. An exhaust gas muffler for internal combustion engines comprising: anelongated shell having an inlet at one end and an outlet at the otherend and gas passage means connecting the inlet and outlet; a transversepartition means inside the shell subdividing it into first and secondlongitudinally adjacent chambers; said partition means including a wallmember and a passage defining member secured to the wall member; saidpartition means further including a lengthy tu bular passage formed inpart by said wall member and in part by said passage defining member andopening only into one of the chambers whereby the passage serves as aquarter wave length tuner; the centerline of said passage beingsubstantially parallel to the plane of the wall member.

2. A sound attenuating muffler for flowing gases comprising a housinghaving an inlet and an outlet, gas passage means in the housingconnecting the inlet and outlet, partition means in the housing defininga resonator chamber and including a flat wall defining one side of saidchamber; said wall having an opening in it; said chamber beingcompletely closed except for said opening, a channel secured to the wallso that the wall closes the open face of the channel and the combinedwall and channel define a tuning passage; one end of the channel beingclosed and the channel having an outlet; said channel embracing saidwall opening and the closed end of the channel being located adjacentsaid wall opening, the outlet of the channel being located in saidresonator chamber; said tuning passage being closed except for saidopening and said outlet and the length and area of said passage beingselected in relation to the volume of the resonator chamber so that thetuning passage and resonator chamber are tuned to attenuate apredetermined frequency of sound'vibration.

3. A mufi'ler as set forth in claim 2 wherein said channel has an openend forming said outlet.

4. An exhaust gas muffler for internal combustion engines comprising: anelongated shell having an inlet at one end and an outlet at the otherend and gas passage means connecting the inlet and outlet; a transversepartition means inside the shell subdividing it into first and secondlongitudinally adjacent chambers; the secondof said chambers comprisinga closed resonator chamber isolated from said gas passage means; saidpartition means including a wall member separating said chambers and apassage defining member secured to the wall member; said partition meansfurther including a lengthy tubular passage formed in part by said wallmember and in part by said passage defining member; the centerline ofsaid passage being substantially parallel to the plane of the wallmember; said wall having an opening into said passage; said passagehaving an opening into the second of said chambers whereby said passageinterconnects said chambers; the length and area of said passage and thevolume of the second chamber being interrelated to tune them toattenuate a preselected frequency.

5. A muffler as set forth in claim 4 wherein said passage definingmember comprises; a channel shaped part attached

1. An exhaust gas muffler for internal combustion engines comprising: anelongated shell having an inlet at one end and an outlet at the otherend and gas passage means connecting the inlet and outlet; a transversepartition means inside the shell subdividing it into first and secondlongitudinally adjacent chambers; said partition means including a wallmember and a passage defining member secured to the wall member; saidpartition means further including a lengthy tubular passage formed inpart by said wall member and in part by said passage defining member andopening only into one of the chambers whereby the passage serves as aquarter wave length tuner; the centerline of said passage beingsubstantially parallel to the plane of the wall member.
 2. A soundattenuating muffler for flowing gases comprising a housing having aninlet and an outlet, gas passage means in the housing connecting theinlet and outlet, partition means in the housing defining a resonatorchamber and including a flat wall defining one side of said chamber;said wall having an opening in it; said chamber being completely closedexcept for said opening, a channel secured to the wall so that the wallcloses the open face of the channel and the combined wall and channeldefine a tuning passage; one end of the channel being closed and thechannel having an outlet; said channel embracing said wall opening andthe closed end of the channel being located adjacent said wall opening,the outlet of the channel being located in said resonator chamber; saidtuning passage being closed except for said opening and said outlet andthe length and area of said passage being selected in relation to thevolume of the resonator chamber so that the tuning passage and resonatorchamber are tuned to attenuate a predetermined frequency of soundvibration.
 3. A muffler as set forth in claim 2 wherein said channel hasan open end forming said outlet.
 4. An exhaust gas muffler for internalcombustion engines comprising: an elongated shell having an inlet at oneend aNd an outlet at the other end and gas passage means connecting theinlet and outlet; a transverse partition means inside the shellsubdividing it into first and second longitudinally adjacent chambers;the second of said chambers comprising a closed resonator chamberisolated from said gas passage means; said partition means including awall member separating said chambers and a passage defining membersecured to the wall member; said partition means further including alengthy tubular passage formed in part by said wall member and in partby said passage defining member; the centerline of said passage beingsubstantially parallel to the plane of the wall member; said wall havingan opening into said passage; said passage having an opening into thesecond of said chambers whereby said passage interconnects saidchambers; the length and area of said passage and the volume of thesecond chamber being interrelated to tune them to attenuate apreselected frequency.
 5. A muffler as set forth in claim 4 wherein saidpassage defining member comprises; a channel shaped part attached tosaid transverse partition; said channel having a closed end adjacent thewall opening and the other end of the channel being open to form theopening into the second chamber.